## page was renamed from IIO cleanup
''Mentors:'' [http://kernelnewbies.org/OctavianPurdila Octavian Purdila], [http://kernelnewbies.org/DanielBaluta Daniel Baluta]

= Experimenting with IIO subsystem =

For this we will use two kernel modules found in {{{drivers/staging/iio}}}:

 * {{{iio_dummy_evgen.ko}}} - generates ''fake'' events interrupts to be used by the {{{iio_dummy}}} example driver
   * implementation for this module is in {{{iio_dummy_evgen.c}}}
 * {{{iio_dummy.ko}}} - example IIO driver to demonstrate existing functionality
   * core implementation can be found in {{{iio_simple_dummy.c}}}
   * buffer functionality is implemented in {{{iio_simple_dummy_buffer.c}}}
   * events functionality is implemented in {{{iio_simple_dummy_events.c}}}

== Dummy modules compilation ==

You need to select the following config options:
 * {{{CONFIG_IIO_DUMMY_EVGEN}}} - for building {{{iio_dummy_evgen}}} kernel module
 * {{{CONFIG_IIO_SIMPLE_DUMMY}}} - for building {{{iio_dummy}}} kernel module
   * {{{CONFIG_IIO_SIMPLE_DUMMY_EVENTS}}}, {{{CONFIG_IIO_SIMPLE_DUMMY_BUFFER}}} should be selected for events and buffer functionality.

Use the following commands for modules compilation:
 * {{{$ make drivers/staging/iio/iio_dummy_evgen.ko}}}
 * {{{$ make drivers/staging/iio/iio_dummy.ko}}}

Use the following commands for module loading:
 * {{{$ insmod iio_dummy_evgen.ko}}}
 * {{{$ insmod iio_dummy.ko}}}

Task 01:

 * Show that the modules were successfully loaded . Send an email to mentors listed at the top of the page, with the output of the following commands
   * lsmod
   * ls -l /sys/bus/iio/devices/
   * ls -l /sys/bus/iio/devices/iio:device0/
   * ls -l /sys/bus/iio/devices/iio_evgen/


== IIO event monitor ==

IIO event monitor is an user space example application which reads events from IIO layer and pretty prints the results. Implementation can be found in {{{iio_event_monitor.c}}} under {{{iio/drivers/staging/iio/Documentation}}}. [[BR]]

Task 02:

    * compile {{{iio_event_monitor.c}}} to obtain an executable called {{{iio_event_monitor}}}. Send an email with the command used for compilation to mentors listed at the top of the page.

== IIO sysfs attributes ==

IIO sysfs attributes should all be documented in {{{Documentation/ABI/testing/sysfs-bus-iio}}}. Have a look at this file, with a focus on the following entries:
 * /sys/bus/iio/devices/iio:deviceX
 * /sys/bus/iio/devices/triggerX
 * /sys/bus/iio/devices/iio:deviceX/buffer
 * /sys/bus/iio/devices/iio:deviceX/events

Task 03: Add missing ABI Documentation
 * this task asks you to find missing ABI documentation in {{{Documentation/ABI/testing/sysfs-bus-iio}}} (for example look at this [http://www.spinics.net/lists/linux-iio/msg15203.html patch])
 * the key structure to be analyzed is [http://lxr.free-electrons.com/source/include/linux/iio/iio.h#L217  struct iio_chan_spec]
 * use {{{drivers/staging/iio/iio_simple_dummy.c}}} for testing adding new channels to {{{iio_dummy_channels[]}}} array. Then look for the attributes names in {{{/sys/bus/iio/devices/iio:device0}}} and check to see if they 
are documented in {{{Documentation/ABI/testing/sysfs-bus-iio}}}
 * make sure that the undocumented ABI has at least one user driver in {{{drivers/iio/}}} or {{{drivers/staging/iio/}}}